Molecular Biology Commons^™

Developing Antibodies Against Galectin-3 And Galectin-9 To Target Endometriosis, Ashleigh Burger, Noah Farnsworth, Jared J. Reisnouer, Cheyenne Vue

2026 Symposium

Endometriosis is a disease characterized by pelvic pain and the formation of endometrial-like tissue on the outside of the uterine lining. This condition affects nearly 10% of women across the globe and confirming whether someone has endometriosis requires visualization in surgery. While the specific causes of this disease remain unclear, the over-expression of the Galectins 3 and 9 in ectopic endometrial tissues suggests a role in the development and maintenance of the condition. Monoclonal antibodies (mAbs) are highly specific proteins with potential as diagnostic or treatment tools. The goal of this study is to generate antibodies against Gal3 and Gal9. …

Predicting And Decoding Allosteric Binding Sites Using Protein Language Models And Structure-Based Machine Learning: An Energy Landscape-Guided Explainable Ai Framework, Kamila Riedlová, Vít Skrhák, William G. Gatlin, Max Ludwick, Lucas Turano, Marian Novotný, David Hoksza, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Computational prediction of allosteric binding sites in protein structures remains a persistent challenge, as these regulatory pockets evade detection by both sequence-based and structure-based algorithms. Both computational and physical origins of this predictive asymmetry remain insufficiently understood. In this study, we systematically examine the determinants of binding site predictability using a dual framework that integrates a fine-tuned protein language model and the structure-based method P2Rank as complementary tools probing a diverse data set of 453 human kinases, together with a physics-based interpretability layer derived from energy landscape frustration analysis. Both predictors exhibit a sharp and reproducible dichotomy on protein kinases, …

Abnormal Trafficking And Processing Of Multiple Matrix Metalloproteinases Drive Cartilage Defects In Congenital Disorders Of Glycosylation, Chia-Lun Wu

All Dissertations

Congenital Disorders of Glycosylation (CDG) are rare metabolic diseases caused by defects in glycosylation. Despite identification of over 200 CDG types, the mechanisms linking glycosylation defects to diverse clinical phenotypes remain unclear. This dissertation uses zebrafish models of PMM2-CDG and STT3-CDG to redefine CDG pathogenesis, shifting from a simple glycan deficiency model to one involving disrupted cellular spatial organization.

We identify a protease-dependent pathway underlying craniofacial cartilage defects. Specifically, defective proteolytic processing of N-cadherin, a key adhesion molecule in chondrogenesis, is a central driver of pathology. We further uncover an unconventional trafficking mechanism in which ER stress and altered secretory …

Understanding The Role Of Toxs As A Bile Sensing Component Of The Toxrs Virulence Regulatory System In Vibrio Spp., Minje Kim

Dartmouth College Ph.D Dissertations

Pathogenic Vibrio bacteria, such as V. cholerae and V. parahaemolyticus, colonize in the human small intestine to cause severe gastrointestinal disease. During the infection, these bacteria encounter bile salts, antimicrobial cholesterol metabolites secreted into the intestine. Pathogenic Vibrio species have evolved to utilize bile salts as signals to regulate virulence. The signaling depends in part on ToxRS, a conserved co-component transmembrane transcription regulator. ToxRS consists of the transcription factor ToxR and its membrane-tethered binding partner ToxS. ToxS is required for ToxR stability and full transcriptional activity. Although bile salts are known to influence ToxRS-dependent virulence gene expression, the molecular …

Optimizing Itpa R178c Assays Via Hplc, Jared J. Reisnouer, Wally D. Pines

2026 Symposium

Two of the major nucleotide bases in DNA and RNA (Adenine and Guanine) are derived from the purine Inosine Monophosphate (IMP). IMP may occasionally form the noncanonical nucleotide Inosine Triphosphate (ITP) within the cell and become incorporated into DNA during replication, leading to potentially lethal errors. To combat this, human cells produce the “housekeeping” enzyme Inosine Triphosphatase (ITPA) to revert ITP to IMP. A mutation of this protein that replaces the 178th amino acid Arginine with Cysteine (R178C) is associated with a fatal infantile encephalopathy. Previous assessments of enzyme-substrate binding and catalysis for ITPA variants have been run at a …

Exploration Of A Relationship Between The Activities Of Trail And 4’-Trifluoromethoxychalcone., Abigail C. Ernst

Undergraduate Theses

Cancer is the overgrowth of dysregulated or mutated cells that affects 1 in 3 Americans. Chalcones are natural products with many possible derivatives, such as 4’-trifluromethoxychalcone (4TF), developed in Dr. Krzysiak’s lab, which exhibit anticancer activity against cancer cell lines. Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) is a tumor surveillance cytokine that acts on two receptor types: death receptors and decoy receptors. One way cancer cells can become resistant to TRAIL is by upregulating decoy receptors and/or downregulating death receptors. In this study, MTS assays evaluated the potential relationship between TRAIL and 4TF that sensitizes A549 cells to TRAIL. The …

Discovering Drug-Like Compounds By Targeting Protein-Protein Interactions Using A Yeast-3-Hybrid System, Chesley C. Blake

Senior Theses

Protein-protein interactions are important targets in cancer biology as they can make historically “undruggable” proteins viable drug targets. However, the current approach to targeting protein-protein interactions relies on the use of small molecule drugs, which have low efficiencies as they must cover a large surface area of the interaction. Further, traditional drug therapies often lead to off-target toxicity, limiting therapeutic specificity. The objective of this project is to develop a selection system in yeast to identify short peptide sequences that can disrupt protein-protein interactions specific to cancer cells. Following proof of principle and development of the AH109 yeast strain having …

Defining Rna Oligonucleotides That Reverse Deleterious Phase Transitions Of Rna-Binding Proteins With Prion-Like Domains., Lin Guo, Jacob Mann, Jocelyn Mauna, Katie Copley, Hejia Wang, Jack Rubien, Cristian Bergmann, Jenny Carey, Jessica Merjane, Marilyn Ngo, Jiazhen Xu, Hana Odeh, Jiabei Lin, Bo Lim Lee, Laura Ganser, Emma Robinson, Kevin Kim, Anastasia Murthy, Tapas Paul, Bede Portz, Amanda Gleixner, Zamia Diaz, Ashleigh Smirnov, George Padilla, Ellen Lavorando, Carolann Espy, Yulei Shang, Eric Huang, Alessandra Chesi, Nicolas Fawzi, Sua Myong, Christopher Donnelly, James Shorter

Department of Biochemistry and Molecular Biology Faculty Papers

RNA-binding proteins (RBPs) with prion-like domains (PrLDs), such as FUS and TDP-43, condense into functional liquids, which can transform into pathological fibrils that underpin fatal neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD). Here, we define short RNAs that prevent FUS fibrillization by promoting liquid phases and distinct short RNAs that prevent and reverse FUS condensation and fibrillization. These activities require interactions with multiple RNA-binding domains of FUS and are encoded by RNA sequence, length, and structure. We define a short RNA that dissolves cytoplasmic FUS aggregates, restores nuclear FUS, and mitigates FUS toxicity in optogenetic models and ALS …

Potential Environmental Triggers Of Goodpasture's Disease And The Role Of The Sulfimine Crosslink, Colton S. Miller, Andrea Florian, Elena Pokidysheva

SPARK Symposium Presentations

Goodpasture’s syndrome (GP) is an autoimmune disorder that primarily affects kidneys and lungs. The main issue for patients with Goodpasture's syndrome is the binding of autoantibodies to the glomerular basement membrane (GBM), which hinders the filtration of blood. A key characteristic of Goodpasture's syndrome is the presence of autoantibodies that target the NC1 domain of the α345 isoform of type IV collagen, a crucial component of the GBM that provides structural support and is critical for filtration function. Sulfilimine bonds crosslink the collagen IV NC1 hexamers, contributing to the stabilization of these structures. A recent clinical case of recurring Goodpasture's …

Molecular Mechanisms And Metabolic Consequences Of Glucocorticoid Resistance, Genesee J. Martinez

Theses and Dissertations--Pharmacology and Nutritional Sciences

Glucocorticoids are vital steroid hormones that govern metabolism, stress responses, and immune functions through intricate, tissue-specific mechanisms, both genomic and non-genomic. These hormones bind to the glucocorticoid receptor (GR), which then acts as a transcription factor to modulate gene expression. Chronic elevation of glucocorticoid levels may lead to glucocorticoid resistance, resulting in adiposity, inflammation, and insulin resistance, thereby adversely affecting multiple metabolic tissues. Whether produced endogenously or administered exogenously, excessive, chronic glucocorticoid concentrations impair glucocorticoid signaling. Although there are two primary isoforms of the receptor, GR⍺ and GRβ, only GR⍺ interacts with glucocorticoids.Through the research conducted in this dissertation, we …

Exploring Anticholinergic Neurotoxicity: Diphenhydramine's Impact On Neuro-2a Cell Morphology, Expression, And Viability, Jordan B. Mcintyre

Honors Undergraduate Theses

Anticholinergic medications, such as diphenhydramine (commonly known as Benadryl), are increasingly recognized for their association with cognitive impairment and neurodegenerative disease. These medications, which inhibit the action of acetylcholine, a neurotransmitter essential for the formation and utilization of the central and peripheral nervous system, have been implicated in conditions such as dementia and may impact fundamental cellular processes like neurogenesis and cell proliferation. This study investigates the effects of diphenhydramine on neurogenesis when introduced to Neuro-2a cells during differentiation. For all studies cells were plated on coverslips or in 6-well plates with differentiation media containing 0 ng/mL, 50 ng/mL, …

Dna Extrusion Size Determines Pathway Choice During Cag Repeat Expansion, Mayuri Bhatia, Ashutosh S. Phadte, Anna Lakhina, Anthony R. Monte Carloi Iii, Sarah Barndt, Anna Pluciennik

Department of Biochemistry and Molecular Biology Faculty Papers

DNA triplet repeat expansion causes several primarly neurological disorders like Huntington's disease, myotonic dystrophy type 1, and fragile-X related disorders. There is general consensus that recognition of extrahelical extrusions or hairpin-loop structures (formed by strand slippage) by the DNA mismatch repair protein MutSβ leads to repeat expansion by a mutagenic process. By contrast, the FAN1 nuclease attenuates triplet repeat expansion, the molecular basis of which was explained by our recent finding that FAN1 nuclease cleaves and initiates removal of extrahelical extrusions. Here we show that extrusions containing two or more triplet repeats are subject to recognition and processing by either …

Targeting The Bcl2 Family: Advances And Challenges In Bh3 Mimetic-Based Therapies, Nabanita Mukherjee, James Sheetz, Yiqun Shellman

Student Papers, Posters & Projects

The BCL2 family of proteins plays a pivotal role in regulating apoptosis and cellular homeostasis, making them critical therapeutic targets in cancer and other diseases characterized by pathological cell survival. BH3 mimetics, small molecules that selectively inhibit anti-apoptotic BCL2 family members, have achieved significant clinical success, particularly in hematologic malignancies. However, several challenges remain, including resistance mechanisms, toxicity (such as MCL1 inhibitor-associated cardiotoxicity), and the intricate balance between apoptotic and non-apoptotic functions. This review provides a comprehensive overview of BCL2 family biology, the development and clinical application and outcomes of BH3 mimetics, and the emerging resistance mechanism known as double-bolt …

Effect Of Histidine Tag On The Enzymatic Activity Of Pseudolysin And Its Interaction With The Streptomyces Metalloprotease Inhibitor (Smpi) Protein, Adewale Adeboye Adewole

Electronic Theses and Dissertations

Pseudolysin (PLN) protein is a major virulent factor in Pseudomonas aeruginosa infection. PLN belongs to the family of zinc-dependent metalloproteases. It is naturally inhibited by a smaller protein called streptomyces metalloprotease inhibitor (SMPI), secreted by Streptomyces nigrescens. Previous and current studies demonstrate that the interaction between PLN and SMPI offers unique mechanistic insights for drug development against infections caused by P. aeruginosa. This study investigated the effect of N-terminal Histidine (His) tag on the enzymatic activity of PLN and its interaction with SMPI. His-tagged PLN and SMPI proteins were expressed in bacteria and purified by affinity chromatography …

Developing A Small Molecule To Inhibit Hsf1 Expression In Cancer And Evaluating Natural Genetic Variation In Small Molecule Toxicity., Michaela Kendal Foley

Theses and Dissertations

Each year cancer affects nearly 20 million people worldwide and genetic differences across populations can impact cancer onset and progression. Specifically, tumors with high levels of HSF1, the master regulator of the cytoprotective heat shock response (HSR), are correlated with poor patient outcomes in multiple cancers such as prostate, breast, and melanoma. Subsequently, the development of pharmacological inhibitors of HSF1 represents a promising strategy for anticancer therapeutics. Using a luciferase-based transcriptional reporter, two small molecule libraries were screened for inhibitors of HSF1 expression in human embryonic kidney cells, yielding ten compounds that decrease HSF1 expression. To identify if cancer lines …

Impact Of Tumor Cell Expressed Cd38 On Metastasis And Immune Evasion In Breast Cancer, Tanvi Visal

Dissertations and Theses (Open Access)

Triple-negative breast cancer (TNBC) is a highly metastatic breast cancer subtype. The epithelial-to-mesenchymal transition (EMT) of cancer cells is a key feature of the metastatic cascade and is not a binary process but often generates malignant cells with both epithelial (E) and mesenchymal (M) traits known as hybrid EM cells. Recent studies highlight the enhanced metastatic potential of the hybrid EM cells. However, molecular insights and targetable vulnerabilities within hybrid EM remain elusive. We discovered that hybrid EM murine tumors are enriched in CD38, an immunesuppressive molecule associated with worse clinical outcomes in liquid malignancies but relatively understudied in solid …

Investigation Of The Effects Of The Peptidylarginine Deiminase Inhibitor Cl-Amidine On Apoptosis And Gene Expression In Ovarian Cancer, Victoria Walden

Longwood Senior Thesis Proposal

Peptidylarginine deiminases (PADs) are a family of enzymatic proteins responsible for the conversion of arginine and methylarginine residues to citrulline. This conversion is important for several key cellular processes including transcriptional gene regulation. Recently, a link has been established between overexpression of a particular PAD, PAD4, and the accelerated progression of both autoimmune diseases and cancers. Ovarian cancer exhibits heightened levels of PAD4 in affected cells. High levels of PAD4 are associated with the formation of neutrophil extracellular traps (NETs) that promote cancer metastasis, and downregulation of the p53 apoptotic pathway. Thus, it is important to explore inhibitors of PAD4. …

Domain Communication In Bifunctional Proline Utilization A From Sinorhizobium Meliloti, Emma Bitterman

Honors Program: Senior Projects (Public)

The reduction potential of flavin bound to Sinorhizobium meliloti proline utilization A (SmPutA) is beneficial in providing vital information on enzyme activity and the active site environment. Flavin is crucial in biological metabolism such as aerobic respiration and other important processes like oxygen activation that are catalyzed by flavin-dependent enzymes. (4). In this study, we seek to determine whether the redox potential of SmPutA-bound flavin can be used to characterize potential long-distance communication and analyze the possibilities of inactivation reversibility. SmPutA is a large bifunctional enzyme that catalyzes the overall oxidation of proline to glutamate via two catalytic domains (1). …

The Guanine Nucleotide Exchange Factor Ric-8a Regulates The Sensitivity Of Constitutively Active Gαq To The Inhibitor Ym-254890, Morgan Dwyer, Jiansong Luo, Tyson Todd, Kendall Blumer, Gregory Tall, Philip Wedegaertner

Department of Biochemistry and Molecular Biology Faculty Papers

Heterotrimeric G proteins are stimulated under normal circumstances by G protein-coupled receptors to promote downstream intracellular signaling. Mutations can occur in αq at glutamine 209 (Q209) that cause constitutive, G protein-coupled receptor independent signaling due to disruption of GTPase activity. Specifically, Q209L/P mutations are oncogenic drivers of uveal melanoma. YM-254890 (YM) has been shown to selectively inhibit both WT and constitutively active (CA) αqQ209L/P by preventing the release of GDP and exchange for GTP, thereby halting downstream signaling. Because αqQL/P are thought to be primarily GTP-bound and GTPase deficient, the current mechanistic understanding of YM inhibition needs further investigation to …

Tdp43 Autoregulation Gives Rise To Dominant Negative Isoforms That Are Tightly Controlled By Transcriptional And Post-Translational Mechanisms, Megan M. Dykstra, Kaitlin Weskamp, Nicolás B. Gómez, Jacob Waksmacki, Elizabeth Tank, M. Rebecca Glineburg, Allison Snyder, Emile Pinarbasi, Michael Bekier, Xingli Li, Morgan R. Miller, Jen Bai, Shameena Shahzad, Neha Nedumaran, Clare Wieland, Corey Stewart, Sydney Willey, Nikolas Grotewold, Jonathon Mcbride, John J. Moran, Aditya V. Suryakumar, Michael Lucas, Peter M. Tessier, Michael Ward, Peter K. Todd, Sami J. Barmada

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The nuclear RNA-binding protein TDP43 is integrally involved in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Previous studies uncovered N-terminal TDP43 isoforms that are predominantly cytosolic in localization, prone to aggregation, and enriched in susceptible spinal motor neurons. In healthy cells, however, these shortened (s)TDP43 isoforms are difficult to detect in comparison to full-length (fl)TDP43, raising questions regarding their origin and selective regulation. Here, we show that sTDP43 is created as a by-product of TDP43 autoregulation and cleared by nonsense-mediated RNA decay (NMD). sTDP43-encoding transcripts that escape NMD are rapidly degraded post-translationally via the proteasome …

Nls-Binding Deficient Kapβ2 Reduces Neurotoxicity Via Selective Interaction With C9orf72-Als/Ftd Dipeptide Repeats, Kevin Kim, Amandeep Girdhar, Maria Elena Cicardi, V. Kankate, Miyuki Hayashi, Ruoyu Yang, Jenny Carey, Charlotte M Fare, James Shorter, Gino Cingolani, Davide Trotti, Lin Guo

Department of Biochemistry and Molecular Biology Faculty Papers

Arginine-rich dipeptide repeat proteins (R-DPRs) are highly toxic proteins found in patients with C9orf72-linked amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD). R-DPRs can cause toxicity by disrupting the natural phase behavior of RNA-binding proteins (RBPs). Mitigating this abnormal phase behavior is, therefore, crucial to reduce R-DPR-induced toxicity. Here, we use FUS as a model RBP to investigate the mechanism of R-DPR-induced aberrant RBP phase transition. We find that this phase transition can be mitigated by Kapβ2. However, as a nuclear import receptor and phase modifier for PY-NLS-containing RBPs, the function of WT Kapβ2 could lead to undesired interaction with its …

Characterizing And Targeting The Non-Catalytic Functions Of Phosphatase Of Regenerating Liver 3 (Prl-3) In Oncogenesis And Cancer Progression, Jeffery T. Jolly

Theses and Dissertations--Molecular and Cellular Biochemistry

Phosphatase of Regenerating Liver 3 (PRL-3) is frequently upregulated in various cancers and is associated with poor patient prognosis. Although traditionally studied for its phosphatase activity, PRL-3 also interacts with the CNNM family of magnesium transporters through its catalytic site, and these two functions are mutually exclusive at any given time. Most previous studies relied on a commonly used PRL-3 mutation that disrupts both phosphatase activity and CNNM binding, making it challenging to determine which function drives its oncogenic effects. To address this gap in the field, I utilized a panel of PRL-3 mutants that selectively disrupt either phosphatase activity …

Caspases Protect Against Hyperglycemia Induced Necroptosis-Like Cell Death In Brain Endothelial Cells, Aleena S. Mathew

Theses and Dissertations

Acute diabetes characterized by high spikes in blood glucose levels in association with severe hyperglycemia can lead to an increased risk of ischemic stroke in the brain. To better understand high blood glucose levels, hyperglycemia, in the brain we explored its effects on endothelial cells. Endothelial cells line the inner walls of blood vessels and are directly impacted in hyperglycemia. Brain endothelial cells are a major component of the blood brain barrier (BBB) which tightly regulates the brain’s microenvironment. The type of cell death such as apoptosis, caspase dependent, or necroptosis, caspase independent, can exacerbate diabetes associated complications. There is …

Swinging Lever Mechanism Of Myosin Directly Shown By Time-Resolved Cryo-Em, David P. Klebl, Sean N. Mcmillan, Cristina Risi, Eva Forgacs, Betty Virok, Jennifer L. Atherton, Sarah A. Harris, Michele Stofella, Donald A. Winkelmann, Frank Sobott, Vitold E. Galkin, Peter J. Knight, Stephen P. Muench, Charlotte A. Scarfi, Howard D. White

Department of Biomedical and Translational Sciences Faculty Publications

Myosins produce force and movement in cells through interactions with F-actin¹. Generation of movement is thought to arise through actin-catalysed conversion of myosin from an ATP-generated primed (pre-powerstroke) state to a post-powerstroke state, accompanied by myosin lever swing²,³. However, the initial, primed actomyosin state has never been observed, and the mechanism by which actin catalyses myosin ATPase activity is unclear. Here, to address these issues, we performed time-resolved cryogenic electron microscopy (cryo-EM)⁴ of a myosin-5 mutant having slow hydrolysis product release⁵,⁶. Primed actomyosin was predominantly captured 10 ms after …

Redox Control In A Fused Electron Transfer Flavoprotein From A Thermophilic Archaeon And Expanded Significance Of A Hydrogen Bond From A Conserved Histidine Residue That Contributes To Flavin Redox Tuning And Activation For Covalent Modification, Debarati Das

Theses and Dissertations--Chemistry

In absence of O₂ as terminal electron acceptors in anaerobic bacteria and archaea, carbohydrate metabolism is 15 times less efficient compared to aerobic energy metabolism resulting in energy deficit conditions. Despite their meager resources these anaerobes were able to generate H₂ and a chemiosmotic potential able to drive energy demanding reactions such as CO₂ or N₂ fixation. These observations raised concerns as production of high energy reductants (H₂) from mediocre fuels (NADH) defied the laws of thermodynamics.

In 2008, a known mechanism “electron bifurcation” but with flavins as redox mediators instead of quinones was …

Reversible Degradation Of Peptidoglycan By Lytic Transglycosylases, Aaron Devereaux

Theses and Dissertations (Comprehensive)

Antimicrobial resistance continues to be a burden on the global healthcare system with an estimated cost of billions of dollars and millions of deaths each year. Recently, there has been little to no development on new antibiotics to treat bacterial infection, and any that are developed become resisted to within a few years. Both Gram-positive and Gram-negative bacteria contain a mesh-like layer called peptidoglycan (PG) that surrounds their cells providing strength, cell shape, and protection from their environments. This layer is a polymer of N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) connected via a b-1,4-glycosidic bond, with each strand being cross-linked …

Post-Transcriptional Methylation Of Mitochondrial-Trna Differentially Contributes To Mitochondrial Pathology, Sunita Maharjan, Howard Gamper, Yuka Yamaki, Thomas W. Christian, Robert Y. Henley, Nan-Sheng Li, Takeo Suzuki, Tsutomu Suzuki, Joseph A. Piccirilli, Meni Wanunu, Erin L. Seifert, Douglas C. Wallace, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

Human mitochondrial tRNAs (mt-tRNAs), critical for mitochondrial biogenesis, are frequently associated with pathogenic mutations. These mt-tRNAs have unusual sequence motifs and require post-transcriptional modifications to stabilize their fragile structures. However, whether a modification that stabilizes a wild-type (WT) mt-tRNA would also stabilize its pathogenic variants is unknown. Here we show that the N¹-methylation of guanosine at position 9 (m¹G9) of mt-Leu(UAA), while stabilizing the WT tRNA, has a destabilizing effect on variants associated with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes). This differential effect is further demonstrated, as removal of the m¹G9 …

Cryo-Em Analysis Of Pseudomonas Phage Pa193 Structural Components, Stephano M. Iglesias, Chun-Feng Hou, Johnny Reid, Evan Schauer, Renae Geier, Angela Soriaga, Lucy Sim, Lucy Gao, Julian Whitelegge, Pierre Kyme, Deborah Birx, Sebastien Lemire, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

The World Health Organization has designated Pseudomonas aeruginosa as a critical pathogen for the development of new antimicrobials. Bacterial viruses, or bacteriophages, have been used in various clinical settings, commonly called phage therapy, to address this growing public health crisis. Here, we describe a high-resolution structural atlas of a therapeutic, contractile-tailed Pseudomonas phage, Pa193. We used bioinformatics, proteomics, and cryogenic electron microscopy single particle analysis to identify, annotate, and build atomic models for 21 distinct structural polypeptide chains forming the icosahedral capsid, neck, contractile tail, and baseplate. We identified a putative scaffolding protein stabilizing the interior of the capsid 5-fold …

Predicting Mutation-Induced Allosteric Changes In Structures And Conformational Ensembles Of The Abl Kinase Using Alphafold2 Adaptations With Alanine Sequence Scanning, Nishank Raisinghani, Mohammed Alshahrani, Grace Gupta, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Despite the success of AlphaFold2 approaches in predicting single protein structures, these methods showed intrinsic limitations in predicting multiple functional conformations of allosteric proteins and have been challenged to accurately capture the effects of single point mutations that induced significant structural changes. We examined several implementations of AlphaFold2 methods to predict conformational ensembles for state-switching mutants of the ABL kinase. The results revealed that a combination of randomized alanine sequence masking with shallow multiple sequence alignment subsampling can significantly expand the conformational diversity of the predicted structural ensembles and capture shifts in populations of the active and inactive ABL states. …

Engineered Nls-Chimera Downregulates Expression Of Aggregation-Prone Endogenous Fus, Miyuki Hayashi, Amandeep Girdhar, Ying-Hui Ko, Kevin Kim, Jacquelyn Depierro, Joseph R. Buchler, Nikhita Arunprakash, Aditya Bajaj, Gino Cingolani, Lin Guo

Department of Biochemistry and Molecular Biology Faculty Papers

Importin β-superfamily nuclear import receptors (NIRs) mitigate mislocalization and aggregation of RNA-binding proteins (RBPs), like FUS and TDP-43, which are implicated in neurodegenerative diseases. NIRs potently disaggregate RBPs by recognizing their nuclear localization signal (NLS). However, disease-causing mutations in NLS compromise NIR binding and activity. Here, we define features that characterize the anti-aggregation activity of NIR and NLS. We find that high binding affinity between NIR and NLS, and optimal NLS location relative to the aggregating domain plays a role in determining NIR disaggregation activity. A designed FUS chimera (FUS_IBB), carrying the importin β binding (IBB) domain, is …